package com.neuedu.util;

import java.security.MessageDigest;

public class ShaUtil {
	/**
	 * 利用java原生的摘要实现SHA256加密
	 * @param str 加密后的报文
	 */
	public static String getSHA256(String str){
		MessageDigest messageDigest;
		String encodeStr = "";
		try {
			messageDigest = MessageDigest.getInstance("SHA-256");
			messageDigest.update(str.getBytes("UTF-8"));
			encodeStr = byte2Hex(messageDigest.digest());
		} catch (Exception e) {
			e.printStackTrace();
		}
		return encodeStr;
	}
	/**
	 * 将byte转为16进制
	 */
	private static String byte2Hex(byte[] bytes){
		StringBuffer stringBuffer = new StringBuffer();
		String temp = null;
		for (int i=0;i<bytes.length;i++){
			temp = Integer.toHexString(bytes[i] & 0xFF);
			if (temp.length()==1){
				//1得到一位的进行补0操作
				stringBuffer.append("0");
			}
			stringBuffer.append(temp);
		}
		return stringBuffer.toString();
	}

	public static void main(String[] args){
		System.out.println(getSHA256("admin"));
		System.out.println(getSHA256("123456"));
	}
}